Erecting means for gyro vertical instruments



R. s. CURRY,.JR. I EREGTING XEBIS FOR GYRO VERTICAL INSTRUIENTS Oct. 1,1946.

Original FiledJune 29; 1942 FIG! FIG. .4

' R05??? CURRY, JR BY 7 g WH Patented Oct. 1, 1946 'EREG'IIN G MEANS FORVERTICAL INSTRUMENTS Robert s. Curry, J12, Baldwin; N.'Y., assignor toSperry Gyroscope Company,-lnc., a corporation'cf New York Continuationof applicationSerial No. 448,980,

June 29, 1942.

1944, Serial No. 549,712

17 Claims.

This invention relates generally to gyro vertical or gyro artificialhorizon instruments and particularly concerns a controller by which thehearing case of the instrument is erected, upon tilt,

in a direct path so that the spin axis of the gyro This applicationAugust 16,

rotor is maintained vertical with a minimum of conical oscillation. Thepresent application is a continuation of parent application Serial No.448,980, filed June 29, 1942.

One of the features of the present invention consists in the provisionof a novel type of erecting means for such an instrument in the form ofa. repeater motor which is mounted on the gyro rotor bearing case andpositions an eccentric mass 1 about the normally vertical axis of theinstrument so that it is positioned upon tilt approximately 90 degreesfrom the low side of the gyro casing.

To so position the motor, I employ a gravitationally responsive liquidlevel switch for exciting the repeater motor coils properly to achievethe above result.

Other features and structural details of the invention will be apparentfrom the following description when read in connection with theaccompanying drawing wherein:

Fig. l is a side elevation assembly view with parts in section showingan erecting controller constructed in accordance with the presentinvention embodied for use in a gyro vertical instrument of theartificial horizon indicating type.

Fig. 2 is an enlarged perspective view showing the detail structure of ahalf section of the improved motive controlled erecting means.

3 is a schematic view and wiring diagram showing a desirable electricalarrangement of the parts of the erecting controller, and

Fig. 4 is a view similar to Fig. Sillustrating the electricalarrangement of they parts for a modifled form of controller.

With reference particularly to Fig. 1, the gyro vertical instrument withwhich the present motive controlled erecting means is illustrativelydepicted is shown of conventional form. In the present instance, theconventional type of gyro vertical instrument shown in the drawingprovides the stabilizing means for an artificial horizon indicating typeof gyro controlled device, although it will be understood that suchusage'of the invention is illustrative of a single practical embodimentof the same. As shown, such a device is constructed to include an outercasing I9 having a front window II through which the observer views theposition of horizon reference bar I2 with respect to a mask element I3and a suitable lubber line indication (not shown) which may be providedon the window ll of the device. The horizon reference indication or barl2 for this conventional type of gyro controlled device is of usualform, the same including a long arm.

i 4 which is pivotally mounted at 15 on the gimbal ring support for thegyro vertical instrument. Arm I4 is counterbalanced about its pivot 15by means of the counter weight 16. Movement of the arm 14 andconsequently the reference bar I2 is effected by a suitable linkagearrangement (not shown) which connects the same to the rotor bearingcase of the gyro vertical.

The conventional type of gyro vertical instrument shown in the drawingincludes a universal mounting provided in this instance by the casing H!which provides fore and aft positioned bearings (not shown), withrespect to the craft on which the instrument is mounted, which receivethe trunnio-ns of a gimbal ring I1 so that the same is confined tomovement about a normally horizontal axis. The mask element I3 and pivot[5 for the horizon bar 12 are situated on this ring in the usualfashion. The gyro rotor bearing case I8 of the instrument is alsomounted in a conventional way in the gimbal ring by means or furthersuitable bearings (not shown) situated in the ring and athwartshipextending trunnions, with reference to the craft, one of which isindicated at 19 in the drawing. The athwartship defined axis of therotor bearing case I8 is normally horizontal and is situated inperpendicular relation to the fore and aft located axis of the gimbalring H, the gyro rotor hearing case 18 consequently being universallysupported within the outer casing ID. The gyro rotor (not shown) issituated within the rotor bearing case in a suitable manner, the samespinning about 'a nominally vertical axis. When the case 48 tilts aboutone or both its axes of universal support, the spin axis of the gyrorotor of the instrument correspondingly inclines frm a normally verticalor erected position. The controller of the present invention hereinafterdescribed provides for the maintainence of such position by the directedapplication of atorque about one of the axes of the universal support ofthe instrument. The gyro rotor may be spun pneumatically; electricallyor in any other desired manner, although in the instant case I prefer toemploy an electrically driven rotor which may be of conventionalconstruction and is supplied by a suitable source of three phasealternating current electrical energy such as indicated at 20, in Figs.3 and 4. Such energy is led to the rotor bearing case 13 of theinstrument by way of suitable slip rings (not shown) at the axis of thevase I8 and axis or the ring I! from the exterior of the outer casing I.

With reference also to 2, 3 and i. the motive controlled erecting meansof the present invention is shown to include an electric motor of therepeater or positional type, comprising a stator 2| which is mounted onthe rotor bearing case by means of a hollow vertically extending post22. The lower end of post 22 is suitably fixed in position in the topWall of the gyro rotor bearing case. The stator 2| of the motor mayinclude a plurality of circumferentially located poles 23, each of whichis provided with a radially extending core, in this instance. The statoris wound in polyphase fashion, the windings of the same being indicatedat 24. As shown in Fig. 3, a two phase type of stator winding isutilized whose respective windings 24' and 24" are arranged in 90angular spaced electrical relation. With this type of stator in whichcorresponding groups or pairs of such windings are employed, it will beunderstood that when both sets of windings are energized there will beno resultant magnetic field produced by the stator to efiect movement ofthe electrical rotor of the controlling motor. Fig. 4 showsanalternative form of winding for the stator 2| in which the same is woundin three phase fashion .having corresponding groups of windings 24', 24"and 24" arranged in 60 angular spaced electrical relation. Also, in thisalternative form of the invention there is no magnetic field producedwhen the windings are all energized to move the rotor.

The rotor of the erection controlling means is designated at 25, thesame in this instance surrounding the stator 2| and being formed toinclude a plurality of inwardly extending poles 26 and correspondingcore elements. The rotor 25 is a single phase wound type, the windingfor the same being indicated at 21. Suitable means are provided formounting the rotor for movement about an axis defined by the post 22which axis is also coincident with the spin axis of the gyro rotorcontained Within the gyro rotor bearing case I8. As shown, such mountingmeans includes a base forming holding plate 28, bearing 29 and thrustbearing 30, Fig. 1. The circumferential surface of the plate 28 is alsoprovided with slip rings 3| by which energy is supplied the same by wayof suitable brushes (not shown) mounted on a cover member 32 whichencloses the motor construction. The cover member 32 is, in thisinstance, suitably fixed to the top of the gyro rotor bearing case l8.An unbalancing mass 33 is situated on the rotor plate 28 which isangularly positioned in the operation of the controller so that theweight of the same is effective to exert a torque about one of the axesof universal mounting of the gyro rotor bearing case to restore the spinaxis of the gyro rotor to its normally vertical position, it beingunderstood that such torque is exerted in the proper direction tocorrect the tilted condition of the case.

In order to selectively energize difierent windings of the stator 2| andthereby obtain a directing field which combines with the field of therotor 25 to move the rotor so that the unbalancing mass 33 on the sameis properly positioned, I employ a vertical reference maintainingswitching means which is gravitationally controlled. Such switchingmeans, as shown, is constructed in the form of a liquid levelcontrolling type of switch which is mounted on the bottom of the gyrorotor bearing case |8 by means of the fixed connecting member 34. Theswitch proper is formed of a disc shaped top portion 35 constructed of asuitable insulating material such as porcelain and includes a currentconducting spherically-shaped bottom portion 36 which is fixed to thecover. The chamber provided between the respective parts is filled witha current conducting fluid 31 except for a bubble 38 which moves overthe inwardly disposed face of the cover 35 when the case l8 tilts. Whenthe instrument is properly erected, it will be understood that thebubble 38 is centrally situated with respect to the face of thedisc-shaped cover 35 which it contacts. Reference is made to thecopending application of Muma, Wilson and Haskins, Serial No. 495,298filed July 19, 1943, for Liquid level switches for a more detaileddescription of this considered type of switch.

With reference to Fig. 3, the switch provided for operation with the twophase type of controller constructed in accordance with the presentinvention includes a pair of oppositely disposed contacts 404|!'situated in parallel relation in the switch with respect to the axis ofthe gimbal ring IT or fore and aft axes of the craft. A second pair ofcontacts 4|--4|' are arranged in the switch to be correspondinglyrelated to the axis of the rotor bearing case l8 or athwartship axis ofthe craft.

The circuit connections for the type of erecting means shown in Fig. 2,may be tapped from two of the leads supplying three-phase electricalenergy to spin the gyro rotor if such an arrangement is employed, andmay include lead 42 from the source to the common contact 43 for thefivecontact type of switch shown in this instance. Lead 44 which isanother lead to the sourceof energy supplies energy directly to thestator furnishing the same to both the pairs or sets of windings 24'-24'and 24"24". Leads 45 and 46 are respectively connected to athwartship10- cated switch contacts 4| and 4|. The other windings 24"-24" areconnected to switch contacts 43-40 by way of leads 4'! and 48respectively. A continuous flow of energy is supplied the winding 21 ofthe rotor from the source by way of leads 49 and 50 through the sliprings 3|.

In operation of the erecting controller, it will be understood that whenthe case |'8 tilts so that the spin axis of the gyro rotor departs froma vertical position, the switching means is operable to efiect selectiveenergization of the respective two-phase type windings of thecontrolling motor, such that the unbalanced mass ispositioned 90 degreesfrom the low side of the gyroscope. For example, if the case I8 tiltsbecause of movement of the gimbal ring H, the bubble 38 (Fig. 3) movesin an upward or downward direction as viewed in this figure and opens,or

partially opens, the normally closed switch by uncovering, partially orwholly, either contact 4| 0r 4|. This opens the circuit through windings 24'-24 of the two-phase stator, or lessens the current flowingtherethrough, and the field of the remaining energized windings 24"24"is then effective to move the unbalanced rotor 25 to the position aboveindicated, in which the mass 33 is enabled to exert a torque thatcorrects the tilt of the case in a straight line and Without setting upconical oscillation.

Similar operation of the controller is obtained from the three-phasewound type stator shown in Fig. 4. In this instance, it is necessary toemploy are situated in equidistantly spaced relation from one anotherand from the center of the face of the top portion 35 of the switch.Also, in this form of the invention one or two of the windings may berendered ineffective by the switch. It will also be appreciated that theimproved controller is equally efiective in operation by an electricalrepeater motor of direct current design and the same may be employedwithout departing from the herein disclosed invention. It is alsoapparent that the motor may be controlled by a selective type switch ofthe character shown that operates to make instead of break the circuitto the stator windings.

As many changes couldbe made in the above construction and manyapparently widely different embodiments of this invention could be madewithout departing from the scope thereof, it is intended that all mattercontained in the above description or shown in the accompanying drawingshall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. Erecting means for gyro vertical instruments having a gyro rotorbearing case comprising a motor mounted on the case, having a polyphasewound type stator and a gravitationally unbalanced, single phase Woundtype rotor, a source of electrical energy for said motor, and a verticalreference maintaining switching means responsive to tilt of the case foreffecting selective energization of the winding of said polyphase woundtype stator to move said gravitationally unbalanced rotor to a positionin which the same is efiective to exert a tilt correcting torque on theinstrument.

2. Erecting means for gyro vertical instruments, as claimed in claim 1,in which the stator is two-phase wound.

3. Erecting means for gyro vertical instruments, as claimed in claim 1,in which the stator is three-phase wound.

4. Erecting means for gyro vertical instruments, as claimed in claim 1,in which the switching means is gravitationally controlled.

5. Means for maintaining the spin axis of the gyro rotor of a gyrovertical instrument in a normally erected position comprising thecombination of, a universally mounted gyro rotor bearing case, anerecting controller in the form of a motor, mounted on said case, havinga polyphase wound type stator and a gravitationally unbalanced, singlephase wound type rotor movable about an axi coincident with the spinaxis of the gyro rotor, a source of electrical energy for said motor,and gravitationally operative switching means mounted on and responsiveto tilt of the case for effecting selective energization of the windingsof said polyphase wound type stator to move said gravitationallyunbalanced rotor to an angular position in which the weight of the sameis effective to exert a torque to correct the tilt.

6. Means of the character claimed in claim 5, in which the stator istwo-phase wound and the switching means is provided by a liquid levelcontrolling type switch having five contacts.

'7. Means of the character claimed in claim 5, in which the stator isthree-phase wound and the switching means is provided by a liquid levelcontrolling type switch having seven contacts.

8. Erecting means for artificial horizon type gyro vertical instrumentscomprising the combination of an outer casing, a gimbal ring supabout anormally vertical axis, a repeater motor for maintaining verticalerection of the spin axis of the gyro rotor including amulti-wound'stator and a gravitationally unbalanced rotor,said motorbeing mounted in the case with the axis of the rotor coincident with thespin axis of the gyro rotor, and gravitationally operative switchingmeans responsive to tilt of the case about its axes of support foreffecting selective energization of the windings of said stator to movesaid gravitationally unbalanced rotor to an angular position in whichthe weight of the same is effective to exert a torque about a horizontalaxis substantially normal to the axis of the tilt.

9. Erecting means of the character claimed in claim 8, in which thestator is two-phase wound and the switching means is provided by aliquid level controlling type switch having one common contact and twooppositely disposed pairs of selective contacts.

10. Erecting means of the character claimed in claim 8, in which thestator is three-phase wound and the switching means is provided by aliquid level controlling type switch having one common contact and threeoppositely disposed pairsof selective contacts.

11. A gyro rotor bearing case having an erecting controller mountedthereon in the form of a motor having a polyphase wound type stator andagravitationally unbalanced, single phase wound type rotor movable aboutan axis coincident with the spin axis of the gyro rotor.

12. A gyro rotor bearing case of the character claimed in claim 11, inwhich the stator is two- 40 phase wound.

13. A gyro rotor bearing case of the character claimed in claim 11, inwhich the stator is threephase Wound.

14. A gyro rotor bearing case of the character claimed in claim 11,which includes thereon a; controlling switch of the liquid level type.

15. A gyro rotor bearing case of the character claimed in claim 11, inwhich the stator is twophase wound, and which includes thereon acontrolling switch of the liquid level type having one common contactand two oppositely disposed pairs of selective contacts.

16. A gyro rotor bearing case of the character claimed in claim 11, inwhich the stator is threephase wound, and which includes thereon acontrolling switch of the liquid level type having one common contactand three oppositely disposed pairs of selective contacts.

17. Erecting means for gyro-vertical instru-v ments having a rotorbearing case, comprising a repeater motor mounted on said case having a-ROBERTS. CURRY, Jn.

